Things a Solo Developer Learned While Building 40+ Financial Calculators with Next.js

A solo developer built SorryClub, a web app with 40+ financial calculators using Next.js 16, TiDB Serverless, and Vercel. Key lessons include maintaining consistent code patterns across all tools, keeping core features free to retain SEO traffic while monetizing advanced features, building custom analytics immune to ad blockers, and leveraging AI (GPT-4o) for SEO content generation.